package com.power.sudoku;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.border.LineBorder;
import javax.swing.border.TitledBorder;
import javax.swing.plaf.basic.BasicArrowButton;
import javax.swing.text.*;

public class Sudoku extends JPanel
{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private static final int width = 9;
	private static final int height = 9;
	private int data[][] = new int[height][width];
	private String infoStr = "";

	JButton solve = new JButton("Solve"), reset = new JButton("Reset"), clean = new JButton("Clean");
	BasicArrowButton right = new BasicArrowButton(BasicArrowButton.EAST), left = new BasicArrowButton(BasicArrowButton.WEST);
	JTextField sudokus[][] = new JTextField[height][width];
	JTextPane info = new JTextPane();

	java.util.List<int[][]> solutions;
	private int solutionIdx = 0;

	Sudoku()
	{
		setLayout(null);
		for (int r = 0; r < 3; ++r)
		{
			for (int c = 0; c < 3; ++c)
			{
				JPanel jp = new JPanel();
				jp.setLayout(null);
				jp.setBounds(r * 95 + 5, c * 95 + 5, 95, 95);
				jp.setBorder(new LineBorder(Color.black));

				for (int x = 0; x < 3; ++x)
					for (int y = 0; y < 3; ++y)
					{
						int j = r * 3 + x, i = c * 3 + y;
						sudokus[i][j] = new JTextField();
						sudokus[i][j].setBounds(30 * x + 5, 30 * y + 5, 25, 25);
						sudokus[i][j].setDocument(new NumberLenghtLimitedDmt());
						jp.add(sudokus[i][j]);
					}
				add(jp);
			}
		}

		solve.setBounds(85, 300, 75, 25);
		solve.addActionListener(new SolveAL());
		add(solve);

		reset.setBounds(175, 300, 75, 25);
		reset.addActionListener(new ResetAL());
		add(reset);

		clean.setBounds(265, 300, 75, 25);
		clean.addActionListener(new cleanAL());
		add(clean);

		left.setVisible(false);
		left.setBounds(170, 330, 50, 25);
		left.addActionListener(new prevAL());
		add(left);

		right.setVisible(false);
		right.setBounds(230, 330, 50, 25);
		right.addActionListener(new nextAL());
		add(right);

		JScrollPane jsp = new JScrollPane(info);
		info.setEditable(false);
		jsp.setBounds(300, 5, 140, 285);
		jsp.setBorder(new TitledBorder("Info"));
		add(jsp);
	}

	public boolean solve()
	{
		int i, j;
		for (i = 0; i < height; ++i)
		{
			for (j = 0; j < width; ++j)
			{
				try
				{
					data[i][j] = Integer.parseInt(sudokus[i][j].getText());
					sudokus[i][j].setEditable(false);
				} catch (NumberFormatException e)
				{
					data[i][j] = 0;
					sudokus[i][j].setEnabled(false);
				}
			}
		}

		int n = 9;
		long startTime = System.currentTimeMillis();
		DLX dlx = new DLX(n * n * n + 1, 4 * n * n);
		dlx.setNum(5);
		dlx.solve(data);
		solutions = dlx.getSolutions();

		if (solutions.size() > 1)
			infoStr += "Find multi solutions.\n";
		else if (solutions.size() > 0)
			infoStr += "Find one solution.\n";
		else
			infoStr += "Cannot find a solution.\n";
		infoStr += "Used time: " + (System.currentTimeMillis() - startTime) + " ms\n";

		return update();
	}

	public void reset(int data[][])
	{
		solve.setEnabled(true);
		int i, j;
		for (i = 0; i < height; ++i)
		{
			for (j = 0; j < width; ++j)
			{
				sudokus[i][j].setEnabled(true);
				sudokus[i][j].setEditable(true);
				if (data[i][j] == 0)
				{
					sudokus[i][j].setText("");
				} else
				{
					sudokus[i][j].setText(Integer.toString(data[i][j]));
				}
			}
		}
	}

	boolean update()
	{
		info.setText(infoStr);
		if (solutionIdx >= solutions.size())
			return false;

		left.setVisible(true);
		right.setVisible(true);
		int i, j;
		int solution[][] = solutions.get(solutionIdx);
		for (i = 0; i < height; ++i)
		{
			for (j = 0; j < width; ++j)
			{
				sudokus[i][j].setText(Integer.toString(solution[i][j]));
			}
		}
		return true;
	}

	public static void inFrame(JPanel jp, int width, int height)
	{
		String title = "Sudoku";
		JFrame frame = new JFrame(title);
		frame.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e)
			{
				System.exit(0);
			}
		});
		frame.getContentPane().add(jp, BorderLayout.CENTER);
		frame.setLocationByPlatform(true);
		frame.setSize(width, height);
		frame.setResizable(false);
		frame.setVisible(true);
	}

	public static void main(String[] args)
	{
		int data[][] = { { 8, 0, 0, 0, 0, 0, 0, 0, 0 }, { 0, 0, 3, 6, 0, 0, 0, 0, 0 }, { 0, 7, 0, 0, 9, 0, 2, 0, 0 },

		{ 0, 5, 0, 0, 0, 7, 0, 0, 0 }, { 0, 0, 0, 0, 4, 5, 7, 0, 0 }, { 0, 0, 0, 1, 0, 0, 0, 3, 0 },

		{ 0, 0, 1, 0, 0, 0, 0, 6, 8 }, { 0, 0, 8, 5, 0, 0, 0, 1, 0 }, { 0, 9, 0, 0, 0, 0, 4, 0, 0 }, };
		Sudoku sudoku = new Sudoku();
		sudoku.reset(data);
		inFrame(sudoku, 450, 400);
	}

	class SolveAL implements ActionListener
	{
		public void actionPerformed(ActionEvent e)
		{
			infoStr += "Start solve this sudoku.\n";
			info.setText(infoStr);
			solve.setEnabled(false);
			solve();
		}
	}

	class ResetAL implements ActionListener
	{
		public void actionPerformed(ActionEvent e)
		{
			infoStr += "Reset sudoku data.\n";
			info.setText(infoStr);
			left.setVisible(false);
			right.setVisible(false);
			reset(data);
		}
	}

	class cleanAL implements ActionListener
	{
		public void actionPerformed(ActionEvent e)
		{
			infoStr = "Clean sudoku data.\n";
			info.setText(infoStr);
			solve.setEnabled(true);
			left.setVisible(false);
			right.setVisible(false);
			int i, j;
			for (i = 0; i < height; ++i)
			{
				for (j = 0; j < width; ++j)
				{
					sudokus[i][j].setText("");
					sudokus[i][j].setEnabled(true);
					sudokus[i][j].setEditable(true);
				}
			}
		}
	}

	class prevAL implements ActionListener
	{
		public void actionPerformed(ActionEvent e)
		{
			int size = solutions.size();
			if (size > 0)
			{
				solutionIdx = (solutionIdx - 1 + size) % size;
				infoStr += "The " + (solutionIdx + 1) + "th solution.\n";
				update();
			}
		}
	}

	class nextAL implements ActionListener
	{
		public void actionPerformed(ActionEvent e)
		{
			int size = solutions.size();
			if (size > 0)
			{
				solutionIdx = (solutionIdx + 1) % size;
				infoStr += "The " + (solutionIdx + 1) + "th solution.\n";
				update();
			}
		}
	}

	class NumberLenghtLimitedDmt extends PlainDocument
	{
		/**
		 * 
		 */
		private static final long serialVersionUID = 1L;

		public NumberLenghtLimitedDmt()
		{
			super();
		}

		public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException
		{
			if (str == null)
			{
				return;
			}
			char[] upper = str.toCharArray();
			if (upper[0] > '0' && upper[0] <= '9')
			{
				super.remove(0, getLength());
				super.insertString(0, new String(upper, 0, 1), attr);
			}
		}
	}

}
